Mobile communication services are becoming more and more popular and, with the growth of smartphone devices and mobile Internet, the capability to access the Internet anywhere, anytime is critical for end users. This is especially true for those business travelers who require data access no matter whether they are, using their Home Public Mobile Network (HPMN) or Visited Public Mobile Networks (VPMNs).
When an end user uses the HPMN service, the HPMN provides the end user with a user credential, such as a Subscriber Identity Module (SIM) card for Global System for Mobile Communications (GSM) network. The SIM Card securely stores a secret key (Ki) identifying a mobile phone service subscriber, as well as subscription information, preferences, and other information. The SIM Card also securely stores programmable algorithms A3 and A8, which is the same logic as the A3/A8 algorithm stored in the mobile network's Home Location Register (HLR). The other most important information that the SIM Card stores is the international mobile subscriber identity (IMSI), which is used to uniquely identify the mobile phone service subscriber. The Ki is a 128-bit number paired with the IMSI when the SIM card is manufactured. It is only stored on the SIM card and at the HLR, and is never transmitted across the network on any link.
The SIM Card can be in other similar forms in different mobile networks. The equivalent component in Universal Mobile Telecommunications System (UMTS) networks is a Universal SIM (USIM) card, and in Code Division Multiple Access (CDMA) networks, the equivalent component is a Removable User Identity Module (R-UIM) card.
When a user travels abroad or enters into areas where the HPMN has no direct service coverage, the user can continue to access the service through the HPMN's roaming partners, the VPMNs, via roaming agreements with the HPMN, allowing the HPMN subscribers to use the VPMN's network service for the voice, SMS, and data using the same SIM card. However, the end user needs to pay roaming service fees to the HPMN when the end user uses the service via the VPMN, and the roaming charges are normally much higher, making the final cost of using the VPMN network comparatively expensive. Thus, usually the roaming subscriber of the HPMN will buy a new SIM card for a visited country/region he/she frequently visits and manually insert the new card when s/he enters the country or region. This is inconvenient and expensive.
U.S. Pat. No. 6,466,804 to Pecen, et al. titled “Method and Apparatus for Remote Multiple Access to Subscriber Identity Module” discloses providing multiple client devices in a GSM system remote multiple access to services of a server device. The server device has a single SIM card. Using Pecen's system, information from the server SIM card can be remotely accessed from the client devices over a network connection. But because the server SlM card is local to only a single area, the server provides cheaper local roaming costs in only that area. Furthermore, Pecen's system cannot tailor the roaming based on other service requirements.
There exist demands for alternative solutions that allow a user to efficiently continue to use a mobile service but with competitive low prices and guaranteed quality of service (QoS).